Analysis of Mission Critical Services Radio Access Network Capacity Limitations Over 5G

Abstract

The evolution of Critical Communications has been conditioned by the underlying networks ranging from previous narrowband almost voice-only Private Mobile Radios (PMR) to now multimedia capable broadband Long Term Evolution (LTE) / fifth generation (5G). Due to the nature of critical communications, the 3rd Generation Partnership Project (3GPP) has defined a series of requirements and recommendations to ensure that availability and performance of Mission Critical Services (MCX) are guaranteed specially in massive group communications. However, no study has been conducted to determine if required capacity and scalability conditions in crisis events can be actually satisfied by commercial or even hybrid LTE/5G networks. This paper presents an analysis of the capacity limitations of the MCX voice service over broadband networks in terms of number of concurrent streams that can be served per cell by comprehensively identifying the different transmission and protocols related bottlenecks. The aggregation of such constraints results in a theoretical model for the maximum capacity of LTE/5G, far more realistic than coarse grain estimations that consider overall cell peak rate. Furthermore, a comparison between MCX over LTE and 5G is provided, indicating the ratio of unusable or wasted radio resources to the total amount available. This way not only actual maximum achievable capacity but also a measure of the efficiency in terms of radio resource usage is provided, which is extremely important for the business model behind hybrid deployments. Both results will contribute towards better network dimensioning as well as possible finer tuning of network and service parameters.

Keywords

• 3GPP
• 5G
• broadband communications capacity
• LTE
• MCPTT
• mission critical communications